Endocrine Abstracts

Introduction: Atypical pituitary adenomas are tumors refractory to conventional therapy and characterized by a tendency to rapid progression and high recurrence rate. The aim of the study was to summarize our experience in treatment of atypical pituitary adenomas with temozolomide (TMZ).

Material: 5 patients (3F;2M) aged 44–58 (mean 52.4±5.4) years treated in 2013–2016. We analyzed the results, tolerance and side effects of TMZ.

Results: In three patients (1F;2M) atypical corticotroph adenomas were diagnosed (two Nelson’s syndromes, one Crooke’s cells adenoma), in 1F-prolactinoma resistant to dopamine agonists and in 1F-type 3 silent adenoma (GH+, PRL+). The disease duration ranged 3–23 years (mean 12.4±7.2). Before TMZ implementation, patients underwent a total of 11 transsphenoidal adenomectomies (1–4), four craniotomies, two patients – stereotactic X-ray-therapy, 1 – tomotherapy and 2 – bilateral adrenalectomy. All patients started with TMZ monotherapy 150 mg/m² for five consecutive days with 23-days intervals. The number of courses ranged from 2 to 13. The total remission, lasting from 45 months was obtained in a patient with Crooke’s adenoma, partial remission in one patient with Nelson’s syndrome, transient stable disease (2–4 months) in two patients (with Nelson’s syndrome and somatotropinoma). The prolactinoma was refractory to TMZ. The only side effect was vomiting. In two patients with relapse of Nelson’s syndrome TMZ was used in combination with bevacizumab (six courses) in 1F and in 1M with capecitabine (CAPTEM – five courses), but in both cases it caused short-term disease stabilization.

Conclusion: TMZ is the most effective in treatment of atypical corticotroph adenomas as a single agent and in the first line of treatment, however it is less effective in recurrent form of the disease.